The difference between bonded broadband and load balancing can often be confused. In actual fact, the technologies are quite different.
Load balancing involves multiple lines connected to a load balancing router. When all the bandwidth from one of the lines is in use, the router switches new connections to a second line.
This system can work well depending on it’s uses, however, there are some limitations. Firstly, only the bandwidth from one line can be used for one task. So the incoming bandwidth cannot be combined. This means that if user A is downloading a file, the max download speed will be that of line A. Then if user B starts downloading, this will use line B’s bandwidth.
The load balancing router can distribute the network’s load across multiple lines, but single tasks are limited to single lines.
Bonded broadband consists of multiple lines being used together, so the total download speed is the total of each lines download speed. The data is also transferred in a more reliable way, packets are split before traffic is sent out across the lines on site, then reassembled before reaching the internet.
The most reliable form of bonded broadband uses multiple lines from different providers, therefore if there is a problem with one line you still have some service. Bonded broadband is also faster than load balancing. For instance, if there is a load balancing router with two 5mb connections and you want to download a file, the load balancing router would download the file using one of the 5Mb connections, leaving the second line for other tasks. On the other hand, a bonded broadband service would split the wanted file's packets in two during the download. This means that the file will be downloaded twice as fast, in this example the full 10Mb. This principle also applies for uploading.